THERMODYNAMICS AND KINETICS OF PROTEIN INCORPORATION INTO MEMBRANES
THERMODYNAMICS AND KINETICS OF PROTEIN INCORPORATION INTO MEMBRANES
复制标题
DOI：
10.1073/pnas.80.12.3691
复制
发表时间：
1983-01-01
期刊：
影响因子：
--
通讯作者：
JAHNIG, F
中科院分区：
文献类型：
--
作者：
JAHNIG, F
蛋白质掺入膜的自由能和焓的计算，特别强调迄今为止被忽视的影响，蛋白质的固定化和脂质的膜秩序的扰动。自由能的变化被认为是由疏水效应作为掺入的驱动力和蛋白质固定化效应，这导致从疏水效应获得的自由能的相当大的减少。对于疏水的跨双层α-螺旋的掺入，获得的自由能变化为约-15千卡/摩尔（1卡= 4.184 J），与实验结果一致。脂质扰动效应由于脂质顺序中固有的能量/熵补偿而对自由能变化仅产生很小的贡献。这种效果占主导地位的焓变，产生的值的顺序为100千卡/摩尔与周围的脂质相变的实验观察到的一个显着的温度依赖性。蛋白质掺入的动力学受到脂质扰动效应的影响甚至更强烈，导致掺入速率在脂质相变以下突然降低。
The free energy and enthalpy of protein incorporation into membranes are calculated with special emphasis on the hitherto neglected effects of immobilization of protein and perturbation of lipid order in the membrane. The free energy change is found to be determined by the hydrophobic effect as the driving force for incorporation and the protein immobilization effect which leads to a considerable reduction of the free energy gained from the hydrophobic effect. For incorporation of a hydrophobic, bilayer-spanning alpha-helix, the free energy change obtained is of the order of -15 kcal/mol (1 cal = 4.184 J) in agreement with experimental results. The lipid perturbation effect yields only a small contribution to the free energy change due to an energy/entropy compensation inherent in lipid order. This effect dominates the enthalpy change, giving rise to values on the order of 100 kcal/mol with a pronounced temperature dependence around the lipid phase transition as observed experimentally. The kinetics of protein incorporation are even more strongly affected by the lipid perturbation effect, leading to an abrupt decrease of the rate of incorporation below the lipid phase transition.